A vehicle is generally provided with pillars and rails as parts of a body frame structure. In general, the rails each extend along a boundary line between a side and a top of the vehicle and have: a rail inner that is disposed on a vehicle inner side; a rail reinforcement that reinforces the rail inner; and the like. Note that the reinforcement will hereinafter be abbreviated as “R/F”. Meanwhile, the pillars each extend in a vertical direction of the vehicle and have: a pillar inner that is disposed on the vehicle inner side; a pillar R/F that reinforces the pillar inner; and the like.
An upper end of each of such pillars is joined to the rail. As this joining method, various joining methods are considered. For example, Patent Literature 1 discloses a joining mode in which a portion near an upper end of a center pillar outer reinforcement (a pillar outer R/F) is fixed to a roof rail outer reinforcement (a rail outer R/F) by spot welding, and a portion near an upper end of a center pillar inner (the pillar inner) is held and fixed between the roof rail outer reinforcement (the rail outer R/F) and a roof rail inner (the rail inner).